My preference would actually be just having one of everything. (Of couurse S&W terminology makes that easy 1917,
M25, dashes, or 1905, M10, dashes, M12, dashes, M64, dashes or M40, 42, 640, 940, 642, 442, and all thier dashes...) Of course as the Baron said, no plan survives first contact with the enemy, I have purchased many just because they were interesting, or priced right, or because I could.